Sound-deadening composition



Nov. 12, 1940. J. A, TORRI 2,221,499

SOUND-DEADENING comrosuxou F iled Nov. 8, 1937 wigs.

Patented Nov. 12, 1940 PATENT OFFICE SOUND-DEADENING COMPOSITION Joseph A. Torri, Kankakee, Ill., assignor to J. W. Mortell Company, a corporation of Illinois Application November 8, 1937, Serial No. 173,460

7 Claims.

This invention relates to sound-deadening compositions adapted for use in connection with fabricated sheet metal structures, and the like.

The primary object of the invention is to pro- 6 vide an improved, inexpensive sound-deadening or dampening composition which can be applied directly to the metallic structure to be insulated and serve as a lining itself, or used as an adhesive to secure ordinary sound insulating pads 10 to the structure.

The improved composition may be made of such consistency that it may be applied by means of a brush, spray gun, or trowel. It may be applied as a coating to the under-side of fenders and the like, to prevent wear and deaden the sound resulting from impacts of small articles thrown against the structure. While the invention is intended primarily for use in vehicle bodies, it will be readily understood that it may be equally usea ful in other structures where it is desired to deaden or dampen sounds resulting from impact,

sympathetic vibration, or the like.

Heretofore, compositions for this purpose have employed asphalt materials loaded with light 35 porous materials such as cork, charcoal, rubber, paper, wood, vegetable fibers, corn husks, asbestos fibers. and the like. The present invention constitutes a distinct departure from such practice and it is found that greatly improved results are 30 obtained by using material of opposite characteristics from those heretofore used. In the present invention, I prefer to use fillers of high specific gravity such as sand, silica, and barytes, or metallic fillers such as filings and diminuted turn- 5 ings of iron, lead or other metals. I have discovered that the essential constituent of a sounddeadening composition is a dense, heavy, inert, non-absorbing filler suitably incorporated in a binder. The coating after being applied to the 40 sheet metal structure is dense, tough, non-porous, non-fibrous, compact, and fire-proof. It looks different and feels different from the ordinary sound-deadening compositions heretofore used and produces greatly improved results at a re- 5 duced cost.

The present application is a continua ion in wa t of my application Serial No. 142,716, filed May 14, 1937', Sound-deadening composition.

The invention is illustrated in a preferred em- 50 bodiment in the accompanying drawing, in which:

Figure 1 is a plan view of an automobile door structure provided with a lining of the sounddeadening composition; and Fig. 2 is a broken sectional view, taken as indicated at line 2 of 66 Fig. 1.

In the embodiment illustrated, A designates a sheet metal panel to which is directly attached a sound-deadening composition B. The panel is shown as an ordinary door member but it will be understood that the composition may be applied to the side walls, top wall, or floor of the car for the same effect. Preferably, the composition is applied so as to be from 1 to of an inch in thickness. Of course, the coatings may be thicker, if desired; and will produce improved re- 1 sults but due to the increase in weight of the structure, it is preferred to stay within the limits mentioned in automobile structures.

As stated above there are many dense, heavy, inert materials which are adapted to serve as a 1 suitable loading to mix with an asphalt binder but sand is generally preferred due to its low cost, high specific gravity and other well-known characteristics.

A suitable asphalt emulsion can be prepared in an emulsifying machine by using 50 parts of Mexican asphalt (melting at 105 F.), and heating the material to from 290 to 300 F. 3 parts of clay may be dissolved in 47 parts of water heated to about 90 and this is added to the asphalt and the material emulsified in well-known manner. The asphalt emulsion is very stable and can be mixed with the sand loading at ordinary room temperature without difficulty. An excellent formula utilizing asphalt emulsion is as follows:

Parts by weight Asphalt emulsion 55 Silica sand 45 Practically any clean sand may be used but preferably should not be coarser than that which would pass through a 20 mesh screen. Preferably, the grains are much smaller. The reason for this is that when the material is sprayed on to the under-side of roofs, or the like, it is more difficult to make the composition stick if the granules are large, because there is a tendency for them to bounce off. Of course, after the material is applied and has a chance to set, the size of the granules is of little importance. The larger size granules (20 mesh) are more adapted for use in installations where the material is applied by troweling, for example, on the floor of a car.

The above composition may be air dried or may immediately be subjected to baking temperatures up to 300 F., as are commonly encountered in paint drying ovens. Only about 25% of the composition evaporates and this leaves 75% as the effective sound-deadening material.

deadenina. lows:

Parts by weight llnuisifled asphalt '15 Band 25 duoa its temperaturetothe neighborhood 0170' to90' Randthenpassesintotheseoondemulsiflerwhichmayalsobe'ateroooledandwllldeliver the homocenlsed asnlnlt at a temperature oiwto100'l". '1hishomoenhedasphaltis quitestableandmaybestoreduntilreadyior usewlthaheavminutmaterialmhassand. Asmentlonedabovetheexttahomogenizinlstep lowersthevisooeityottheasphaltandithasthe appearaneeotathinpaint. Thesound-deadenlnzoompositionisthentormedbytheadditlonot averylaraeperoentaaeotsandandithasbeen iound thatsuch a composition can thereflnmbuttheappendedelaimsshould eonstruedasbroadlyaspermissible,inview throuzhoutthemixture.

3. A fluid adhesive sound-deadenina composltionadaptedhbeappliedtoananelsurlaee andtobeoomeseli-sustaininzthereonoomprisinzastablemlxtureotapproximatelyuparts oi ahomogenised emulsion of water and asphalt toetherwith67partaofsand,saldsandbeina substantially uniformly distributed throulhoiit themixture.

4. A fluid adhesive sound-deadenina composition. adapted to he applied to a normally vibratorypanelandtobecomeseli-sustaininsthereonsttemperatures upto300' l".,eomprlsingaa mixtureotanemulsionotasphalthavinza sottenin: point in the order of 105' l". and'ater. together with sand. said sand eolnprisina between45%and85%byweiahto!theoompoaitlon.

5. A fluid adhesive sound-deadenina campedtion.adaptedtobeappliedtoanotma1lyvlbratorypanelandtobeeomeseli-sustainin thneonat temperaturesuptoSOO' 1"..oomprisinsa stablemixtureoianemulaionolamximately. equalpartsoilowsotteninapointasphaltand waterwithaverymallquantityoioolloidalelay together with sand.saidsand comprlsinstrom 45%to85%bywei:htoftheoompoaitionand being substantially uniformly distributed throughoutthemixture.

6. A fluid adhesive sound-deadenina composition,adaptedtobeappliedtoanonnallyviha torypanelandtobeeomeself-sustainlnathereonattemperaturesuntoM'l'Lmomnriainaa I JOBIPHL'lDR-RL 5 CERTIFICATE OF CORRECTION. 5

Patent No. 2,221,1199. November 12, 19110.

JOSEPH A. TORRI. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction, as follows: Page 2, first column, line 55, for "100" read l100-e; and that the said Letters Patent that the same may conform to should be read with this correction therein the record of the case in the Patent Office.

Signed and sealed this 10th day of December, A. D. 1914.0.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents 5 CERTIFICATE OF CORRECTION. 3

Patent No. 2,221,199. November 12, 191m.

JOSEPH A. TORRI.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 55, for "100" read -1l0O- and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 10th day of December, A. D. 19140.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents 

